TER Pebble-Beds of Nottinghamshire, Cannock Chase, and Cheshire, 

 I Crompord in Derbyshire. 



idance represented by XXX. Great abundance represented by X X X X .] 



irnet. 



! 



Aggregates. Leucoxene. Fluorspar. \ Muscovite. 



Remarks on 

 lighter material. 



X X 



XXX 



XXX 



X X 



XXX 



The majority of the 

 quartz -grains are 

 well worn and 

 smoothed ; more 

 or less flattened. 



X X 



XXX 



XXX 



X X 



XXX 



Do. 



x 



XXX 



XXX 







XXX 



Do. 



>< X 



X 



X X X X 



X 



XXX 



Generally rougher 

 than in the 

 above localities; 

 also yellowish, 

 rather than 

 colourless. 



The majority of the 

 quartz -grains are 

 irregular, with 

 rough surfaces. 



Microcline is plen- 

 tiful among the 

 lighter material. 



Dr. Boswortli has informed nie that it is found m the bulk of the 

 old Highland rocks. As it is jDraeticalh' certain, as shown by the 

 distribution of the hea\y minerals (see p. 332), that the tourmaline 

 has not been mainly derived from southern sources, it is to 

 Scottish areas i that we must look for the supply, in larger part, 

 of this mineral. 



TourmaUne, as well as rutile, garnet, fluorspar, and zircon, are 

 probably derived, in part, from local sources. As the Carboni- 

 ferous rocks occurring in the Pebble-Beds (about 4 or 5 per cent.) 



1 M. F. Heddle, 'Mineralogy of Scotland' vol. ii (1901) p. 73; see also 

 ' The Geological Structure of the N.W. Highlands of Scotland ' Mem Geol 

 Surv. 1907, p. 285. 



